Does therapeutic reduction of diastolic blood pressure cause death from coronary heart disease?

Mortality data from 3350 patients who attended the Glasgow Blood Pressure Clinic between 1968 and the end of 1982 were used to examine the hypothesis that lowering diastolic blood pressure (DBP) below 85 mmHg causes death from coronary heart disease (CHD). Analysis of 257 coronary deaths in quintiles of treated DBP showed a significantly nonlinear relation, with the lowest mortality from CHD occurring in the middle quintile (91-98 mmHg). This finding persisted after adjustment for risk at entry, and was independent of sex and pre-existing CHD. In contrast, the relations between treated systolic blood pressure and death from CHD, and treated DBP and death from stroke were linear. For 2355 patients who were untreated at referral there was no relation between the change in DBP during treatment and death from CHD. In our view, however, these findings do not necessarily support the hypothesis that lowering of DBP below 85 mmHg with treatment causes death from CHD. Evidence for this is indirect and inconsistent, and should not, at present, be used as a basis for any change in treatment practice.     

Frame-based immobilization and targeting for stereotactic body radiation therapy.

Frame-based stereotactic body radiation therapy (SBRT), such as that conducted with Elekta's Stereotactic Body Frame, can provide an extra measure of precision in the delivery of radiation to extracranial targets, and facilitates secure patient immobilization. In this paper, we review the steps involved in optimal use of an extra-cranial immobilization device for SBRT treatments. Our approach to using frame-based SBRT consists of 4 steps: patient immobilization, tumor and organ motion control, treatment/planning correlation, and daily targeting with pretreatment quality assurance. Patient immobilization was achieved with the Vac-Loc bag, which uses styrofoam beads to conform to the patient's shape comfortably within the body frame. Organ and motion control was assessed under fluoroscopy and controlled via a frame-mounted abdominal pressure plate. The compression screw was tightened until the diaphragmatic excursion range was < 1 cm. Treatment planning was performed using the Philips Pinnacle 6.2b system. In this treatment process, a 20 to 30 noncoplanar beam arrangement was initially selected and an inverse beam weight optimization algorithm was applied. Those beams with low beam weights were removed, leaving a manageable number of beams for treatment delivery. After planning, daily targeting using computed tomography (CT) to verify x-, y-, and z-coordinates of the treatment isocenter were used as a measure of quality assurance. We found our daily setup variation typically averaged < 5 mm in all directions, which is comparable to other published studies on Stereotactic Body Frame. Treatment time ranged from 30 to 45 minutes. Results demonstrate that patients have experienced high rates of local control with acceptable rates of severe side effects - by virtue of the tightly constrained treatment fields. The body frame facilitated comfortable patient positioning and quality assurance checks of the tumor, in relation to another set of independent set of coordinates defined by the body frame fiducials. The ability to impose abdominal compression proved to be a simple way to reduce target and tissue motion. SBRT with Stereotactic Body Frame enables comfortable patient immobilization and facilitates repeated registering and re-registering of the patient to the frame. With the body frame, large-dose-per fraction treatment is possible for localized tumor deposits with the aim of attaining a more therapeutic result.     

Early detection of colorectal cancer by quantitative fluorescence image analysis of exfoliated cells

Early-stage colorectal cancer is potentially curable. In the present study, we applied quantitative fluorescence image analysis (QFIA) cytology to the detection of experimental colorectal cancer in a rodent model. QFIA cytology combines visual cytologic examination with quantitation of DNA content in single exfoliated cells. Cancer was induced by treating 110 rats with subcutaneous 1,2-dimethylhydrazine. Sequential colon washes were obtained weekly from each animal for 20 weeks. Control animals were treated identically except for the administration of carcinogen. Cells that were cytologically abnormal or had increased DNA content were found starting in the second week. By the eighth week, roughly 50 percent of animals had positive results, and this level remained approximately constant for the duration of the study. Tissue pathologic results were normal during weeks 1 to 7. Dysplasias became common during weeks 8 to 15 whereas most cancers appeared during weeks 16 to 21. These results indicate that QFIA cytology is a highly sensitive method for detecting even preneoplastic changes resulting from carcinogen administration and may prove useful in detecting human colorectal cancer.     

Acetabular salvage in revision total hip arthroplasty using the bipolar prosthesis

From June 1978 to December 1987, 106 revision total hip arthroplasties (THA) for acetabular salvage were performed using a bipolar device. Bone grafting was necessary in most of the patients. Five patients were unavailable for follow-up examination, leaving 96 patients (101 hips), who were followed for an average of two years 11 months (range, two months to 8.5 years). Excellent or good results were obtained in 43 patients; fair results were achieved in 20 patients. Of the nine patients with poor results, five demonstrated roentgenographic evidence of subluxation, and four showed no roentgenographic changes that could explain their persistent pain. Twenty-nine of these bipolar revisions failed and required reoperation. Fourteen of these failures were revised using fixed, cementless devices in conjunction with bone grafting. Ten patients developed deep-wound infection. Nine were treated successfully; the tenth patient died of overwhelming sepsis, her case complicated by multiple infected joint arthroplasties. While the results of revision THA in the present series are not as satisfactory as those reported by others who used fixed cemented or fixed cementless acetabular components, they are superior to the results obtained with excisional arthroplasty, the only alternative in many of these cases.     

Trends in burn admissions in Scotland during 1970–1992

This retrospective study involved analysis of the data of the inpatients discharged with a diagnosis of burns, from various hospitals in Scotland, during the period 1970–1992. There were 51350 such inpatients all over Scotland, with an average annual rate of 2233 cases. Overall burn incidence in actual numbers was 43.7 per cent in < 15 year olds, 41.2 per cent in 15–64 year olds and 15.1 per cent in ≥ 65 year olds. Burn rates per 100 000 population were highest in < 15 year olds and lowest in 16–64 year olds.

The pattern of burn admissions has changed. Since 1987 the highest numbers of burn inpatients were the 16–64 year olds, followed by children, then the elderly. There has been a gradual but sustained fall in burns admissions in all age categories. The downward trend was statistically significant (t = 8.48, 21 d.f., P < 0.001). Though the population of the elderly (≥ 65 year olds) increased by about 13 per cent, the burn admissions and all deaths due to burns did not reveal an upward trend. The population of the old (81 + year olds) increased by 60 per cent during the same period. The incidence of burns was above average when > 80 year olds were considered separately, approaching the levels found in children. However the rate and incidence of burns in the 65–80 year olds resembled that of the younger age group (16–64 year olds).

The total number of deaths due to burns and/or smoke inhalation has declined in all age groups and the decline has been statistically significant (chi-squared = 19.62, 1 d.f., P < 0.001). Maximum number of deaths occurred in ≥ 65 year olds (44 per cent), followed closely by 16–64 year olds (43.5 per cent), and 12.5 per cent of deaths in adolescents and children. The decline was due to improved management of burns and a decrease in the number of patients having large body surface area burns.